Linear action ball bumper



A ril 21, 1965 H. L. SEIDEN ETAL 3,180,645

LINEAR ACTION BALL BUMPER Fil' ed March 14, 1963 INVENTORS. HmMA/v Z. J's/25m United States Patent 3,180,645 LINEAR ACTION BALL BUMPER Herman L. Seiden and Thad Zale, Chicago, Ill., assignors,

by mesne assignments, to Lion Manufacturing Corporation, a corporation of Illinois Filed Mar. 14, 1963, Ser. No. 265,146 3 Claims. (Cl. 273-118) This invention pertains to improvements in bumpers for ball-rolling games of the type in which one or more metal or like ball-s are projected onto an inclined rolldown board to engage various scoring instrumentalities including switches, rebound obstacles, scoring pockets, and the like.

Ball bumpers of the class described are well-known and of considerable variety whether used merely as obstacles or as means for controlling scoring circuits and devices. The principal achievement of the present improvements is to provide a bumper primarily intended to control a scoring switch or the like and characterized by the fact that the switch means can be wholly separate from the bumper and the bumper is provided with a sensitive, strictly linearly-moving switch-operating member actuated by impact of the ball against the bumper post in a wedging action beneath a vertically shiftable dome piece which is lifted by the ball and constrained to linear up and down displacement regardless of the angle of approach or degree of momentum of the ball.

'It is a further object to shape the bumper in a way to prevent stalling of a ball by having a salient projection or radial promontory of the post structure adapted, as in other prior bumper structures, to extend upgrade on the playing board, but unlike prior to stall projections to lie in almost flush vertical alignment beneath the periphery of the vertically movable dome piece so that a ball can approach the bumper nearly head-on down grade and glance ofl. the stall-preventing salient and still wedge in beneath the dome piece sufliciently to actuatethe switch while possessed of a minimum energy content.

A further object is to provide a bumper with verticallylinearly-movable control member and spring means normally depressing the same with a force sufiicient to hold a score switch in open condition, thereby increasing sensitivity and positive switch action because the closure of a the contacts is made to depend upon the spring action of the switch blades them-selves and not the weight or impact of the ball in forcing contacts together as in most prior bumper switch arrangements.

Additional objects and aspects of novelty and utility relate to details of the construction, combination, and mode of operation of the illustrative embodiment hereinafter described in view of the annexed drawing, in which:

FIG. 1 is a perspective view of the new bumper;

FIG. 2 is an enlarged Vertical sectional View of the same and fragmentary portions of a ball rolling board;

FIG. 3 is an illustrative functional diagram viewing the bumper from the top.

Referring to FIG. 1, a preferred embodiment of the bumper comprises a post or upright body section preferably molded from a suitable synthetic plastic for'economical production and having a radially flared foot or base portion 11 adapted to seat upon the surface of a ball-rolling board 12 with a downward extension 13 projecting beyond the lower surface of the board for engagement by a retaining means such as the nut 14 adapted to engage molded threading on said extension.

From one side of the post projects a stall-prevention formation or promontory 16 which is intended to point upgrade on the ball-rolling board to prevent the lodgement of a very slow moving ball in a stalled condition of exact balance at this side of the bumper, the provision of such formations being used in other bumper construc- 3,180,645 Patented Apr. 27, 1965 tions (for example, that shown in US. Patent No. 2,277,274 to Stoner), but in the present construction, as seen particularly in FIG. 3 at Z, being distinguished by the fact that the radial outermost peripheral boundaries of the promontory or stall-preventing projection lie in almost flush vertical alignment beneath the adjacent peripheral boundaries of a circular dome plate 18 surmounting the posts, the purpose of this arrangement being explained more fully hereafter.

The bumper body is provided with a resilient rebound tire or collar 17 beneath the dome plate 18 and the post structure is provided with an internal bore 19which is preferably of some angular cross section (e.g. square) to key with a slideable plunger 20 of like cross section intended to reciprocate within the post, the upper end of said plunger extending upwardly beyond the post for attachment integrally or by other means such as cementing, with the central area of the dome plate 18.

The internal post bore 19 is enlarged at 19A to provide room for a vertically-shiftable collar 21 fixed on the plunger 20 either as a molded part thereof or by cementing or like attachment, the same serving as an abutment for one end of a compression spring 23 surrounding the upper internal reaches of the plunger between the collar and the top of the bore, whereby the plunger and therefore the dome plate, are urged downwardly into a normal, non-hit position, the lower end of the plunger 20A projecting below the attaching foot 13 of the post for engagement with a controlled instrumentality such as the blade switch 30.

The switch means 30 may comprise an ordinary stack switchconsisting of a pair of contact blades 31, 32 secured in a stack of insulating washers 33, the contact blades in this construction being biased normally to close together in circuit-closing relation, and the projecting end 31A of the longer blade being disposed to underlie the lower end 20A of the plunger in a relationship such that the spring-depressed normal position of said plunger flexes the switch blade 31 downwardly (as in dotted lines, FIG. 2) into open-circuit relation relative to the companion blade 32. When a ball engages the bumper appropriately, as illustrated in FIG. 2, the dome plate will be elevated slightly with a corresponding rise of the plunger which is sufiicien-t to permit closure of the switch blades 31, 32 to actuate any desired control means or circuit indicated diagrammatically by the block 35.

It will be apparent from inspection of FIG. 2 that the ball inmoving beneath the dome plate exerts a wedging action on the latter which is at oncesmooth and uniform as distinguished from the prior impact types of switch operation characteristic of the bumpers having built-in switch means, such as rocking contact plates or contact posts of the class typically illustrated in the aforesaid Stoner patent, or US. Patent No. 2,804,514 to Peters, which discloses a form of stack switch wholly separate from the bumper, but actuated by a rocking ball and socket lever.

In consequence of the wedging lift-action of the ball, a slowly moving, slow-energy ball can actuate the plunger and the switch means consistently without contact flutter and does not depend to any extensive degree upon momentumor its energy content and the resulting displacement of the linearly-moveable plunger eliminates the objectionable fluttering type of switch contact closure which is encountered in many prior ball bumper contact arrangements. Moreover, the plunger displacement is consistently responsive whether the ball is moving slowly or strikes the rubber tire and dome at high speed, because rebound does not depend at all upon engagement of the ball with the sensitive dome plate itself, the latter being either positively elevated or not moved at all since it is permitted no sidewise movement or play.

Referring to the functional illustration of FIG; 3 look-' adjacent the promontory will permit the ball to displace the dome and operate the score-control switch means, it being further evident that the same switch-actuating rea spouse will result from engagements of the ball at all other angular approaches about the periphery of the dome piece.

Ball bumpers are known in which there'is a central plunger surmounted by some type of cap which has a sloping or wedge-like under surface normally elevated by a spring means and positively driven by some form of electromagnet triggered on impact ofa ball to cause the wedge cap to descend abruptly and forcibly to throw the ball energetically away from the bumper, such a device being exemplified by the construction shown in US. Patent No. 2,219,898, it being noted that all such devices sufiicient to cause the ball to rebound, for instance as from positions B or C, FIG. 3.

We claim: "1. A ball bumper comprising an upstanding post 'section having a plunger slideable up and down therein with minimized side play, a dome plate secured to the upper end of the plunger with peripheral portions lying circumambiently about the post so that a ball of given diameter striking the post tends to engage the underside of the dome plate and lift the same linearly and elevate the plunger, spring means carried within the post and normally lowering the plunger and its dome plate to a normally depressed position, said plunger having a part projecting beyond the lower margins of the post for engagement with a switch-actuating member of a type operably responsive to up and down motion coaxially with the movement of the plunger.

2. A bumper and switch combination for use on a horizontally-inclined ball-rolling board comprising a switch mounted on the underside of said board and having an operating member disposed for substantially up and down motion to actuate the switch, and a bumper structure including a post body mounted on the upper,

side of said board substantially above said switch operating member, and further including a-vertically linearly reciprocable plunger having a lower end portion overlying and engageable with saidswitch operating member;

a dome plate surmounting the upper end of said plunger and of a diametric configuration to overlie and project radially about the post body at a predetermined level above said board so that a ball of predetermined diameter on the board can engage beneath the dome plate and lift the same with a wedging action to elevate the plunger and cause operation of said switch.

3. The construction of claim 2 further characterized by the provision of a salient promontory projecting in aradial sense from one side of the post body a distance substantially terminating in vertical alignment with a peripheral edge portion of the dome plate whereby a ball engaging the bumper promontory at one particular position angularly thereabout is prevented from displacing the dome plate, said promontory being shaped and confined nevertheless to present a minimum obstruction to the ball from engaging the dome plate on either side thereof immediately adjacent said particular angular posit-ion whereby the lifting action of the ball in engaging dome plate at all other angular positions thereabout is not interfered with.- V

Relerences (Iited by the Examiner UNITED STATES PATENTS 2,219,898 10/40 Hooker 1 273-129 2,277,274 3/42 Stoner et al 2()O-6l.ll 2,793,861 3/57 Konopka,

LOUIS PRINCE, Primary Examiner.

RICHARDC. PINKHAM, Examiner. 

1. A BALL BUMPER COMPRISING AN UPSTANDING POST SECTION HAVING A PLUNGER SLIDEABLE UP AND DOWN THEREIN WITH MINIMIZED SIDE PLAY, A DOME PLATE SECURED TO THE UPPER END OF THE PLUNGER WITH PERIPHERAL PORTIONS LYING CIRCUMAMBIENTLY ABOUT THE POST SO THAT A BALL OF GIVEN DIAMETER STRIKING THE POST TENDS TO ENGAGE THE UNDERSIDE OF THE DOME PLATE AND LIFT THE SAME LINEARLY AND ELEVATE THE PLUNGER, SPRING MEANS CARRIED WITHIN THE POST AND NORMALLY LOWERING THE PLUNGER AND ITS DOME PLATE TO A NORMALLY DEPRESSED POSITION, SAID PLUNGER HAVING A PART PROJECTING BEYOND THE LOWER MARGINS OF THE POST FOR ENGAGE- 